Outgoing calls barred

Two weeks ago I started receiving a "call is barred to companion pay as you go customers" message when trying to make a phone call, in spite of the fact that I'm not a pay-as-you-go customer and also have over R1000 of airtime credit on my contract. After many fruitless attempts by MTN to resolve the problem by merely repeatedly resetting me on their network, asking me to try the sim in another handset, typing in a USSD code to unbar my account, they eventually asked me to request a sim-swap. This I did, but after 3 days of waiting for the sim-swap to go through, I eventually discovered that the sim-swap process had failed. During the whole ordeal not once did MTN follow up with me regarding the resolution of the issue. There is no procedure for escalating a problem with this company and you're left with two meaningless support numbers & operators who merely tell you that they don't know what to do anymore. With more than 7 months left on my contract I find this level of support shocking and utterly disgraceful.